alistair23-linux/drivers/usb/host/xhci-mem.c

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/*
* xHCI host controller driver
*
* Copyright (C) 2008 Intel Corp.
*
* Author: Sarah Sharp
* Some code borrowed from the Linux EHCI driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/usb.h>
#include "xhci.h"
void xhci_mem_cleanup(struct xhci_hcd *xhci)
{
xhci->page_size = 0;
xhci->page_shift = 0;
}
int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
{
unsigned int val, val2;
u32 page_size;
int i;
page_size = xhci_readl(xhci, &xhci->op_regs->page_size);
xhci_dbg(xhci, "Supported page size register = 0x%x\n", page_size);
for (i = 0; i < 16; i++) {
if ((0x1 & page_size) != 0)
break;
page_size = page_size >> 1;
}
if (i < 16)
xhci_dbg(xhci, "Supported page size of %iK\n", (1 << (i+12)) / 1024);
else
xhci_warn(xhci, "WARN: no supported page size\n");
/* Use 4K pages, since that's common and the minimum the HC supports */
xhci->page_shift = 12;
xhci->page_size = 1 << xhci->page_shift;
xhci_dbg(xhci, "HCD page size set to %iK\n", xhci->page_size / 1024);
/*
* Program the Number of Device Slots Enabled field in the CONFIG
* register with the max value of slots the HC can handle.
*/
val = HCS_MAX_SLOTS(xhci_readl(xhci, &xhci->cap_regs->hcs_params1));
xhci_dbg(xhci, "// xHC can handle at most %d device slots.\n",
(unsigned int) val);
val2 = xhci_readl(xhci, &xhci->op_regs->config_reg);
val |= (val2 & ~HCS_SLOTS_MASK);
xhci_dbg(xhci, "// Setting Max device slots reg = 0x%x.\n",
(unsigned int) val);
xhci_writel(xhci, val, &xhci->op_regs->config_reg);
xhci->ir_set = &xhci->run_regs->ir_set[0];
return 0;
fail:
xhci_warn(xhci, "Couldn't initialize memory\n");
xhci_mem_cleanup(xhci);
return -ENOMEM;
}